The invention described herein relates generally to electro-optical connectors. In particular, it relates to connectors that can facilitate the connection of optical fibers with electronic systems.
Due to increasing needs for bandwidth, modem computer and communication networks are placing increasing reliance on optical signal transmission through fiber optic cabling. With fiber optic cabling, data is transmitted using light signals, not electrical signals. For example, a logical xe2x80x9c1xe2x80x9d may be represented by a light pulse of a specific duration and a logical xe2x80x9c0xe2x80x9d may be represented by the absence of a light pulse for the same duration. In addition, it is also possible to transmit at the same time multiple colors of light over a single strand of optic fiber, with each color of light representing a distinct data stream.
Fiber optic cabling is very efficient for transferring data as light signals. However, current technologies are not as efficient in using such light signals in processing data. Therefore, data is typically transferred and stored in various locations before, during and after it is operated on in a computer. There is still no efficient way to xe2x80x9cstorexe2x80x9d light signals representative of data. Networks will therefore likely continue using fiber optics for transmitting data between nodes and silicon chips to process the data within the nodes for the foreseeable future. The interface between the fiber optic cable and the nodes that process the data is therefore problematic because signals need to be converted between the electrical and the light domains.
Fiber optic transceivers, which convert light signals from a fiber optic cable into electrical signals, and vice versa, are used as the interface between a fiber optic line and a computer node. A typical transceiver includes a substrate and one or more electro-optic semiconductor devices mounted on the substrate. These electro-optic semiconductor devices can include optical detectors for converting light signals received over the fiber optic cables into electrical signals and/or optical emitters for converting electrical signals from the semiconductor devices into light signals. A number of fiber optic transceivers are commercially available from a variety of sources including Hewlett Packard, AMP, Sumitomo, Nortel, and Siemens. Some of the drawbacks of existing fiber optic transceivers are that they are generally relatively expensive and relatively difficult to fabricate and in some cases do not permit easy interconnection between optical fiber and a corresponding device. Accordingly, there are continuing efforts to provide improved electro-optic connectors.
To achieve the foregoing and other objects of the invention, a variety of arrangements for positioning at least one optical fiber relative to a photonic device are described. In one aspect of the invention, a connector sleeve is provided that is suitable for receiving a ferrule that holds at least one optical fiber. The connector sleeve is arranged to carry an optical sub-assembly having at least one photonic device. The connector sleeve includes a ridge that operates as a first stop for a connector body into which the fiber optic ferrule is slidably positioned. Also, the connector sleeve includes a longitudinally extending alignment projection that laterally aligns the fiber optic ferrule with respect to the photonic devices of the optical sub-assembly to ensure engagement of alignment pins of the optical sub-assembly with alignment openings in the ferrule.
In another aspect of the invention, a connector having a connector body and a fiber optic ferrule that holds at least one optical fiber is provided. The ferrule is slidably positioned in the connector body. The optical sub-assembly includes a spacer that constrains longitudinal movement of the fiber optic ferrule so that each optical fiber attains a desired standoff with respect to a corresponding photonic device. Another connector embodiment includes a slot and tab arrangement to provide lateral stability in the ferrule.
Another apparatus embodiment includes a connector element having a connector body and a fiber optic ferrule that holds optical fibers, the ferrule slidably positioned inside the connector body. The connector element also includes a connector sleeve configured to receive the connector element and arranged to carry an optical sub-assembly including photonic devices. The sleeve includes a ridge that operates as a first stop for the connector body and includes a longitudinally extending alignment projection that coarsely aligns the fiber optic ferrule laterally with respect to the photonic devices of the optical sub-assembly. The connector element is engaged with the connector sleeve to position the ferrule with respect to the optical sub-assembly such that the optical fiber is correctly positioned relative to a corresponding photonic device.
Aspects of the invention also include a method embodiment for positioning an optical fiber held by a ferrule that is slidably mounted within a connector body, relative to a corresponding photonic device of an optical subassembly carried by a connector sleeve. The method comprises urging the fiber optic ferrule toward the corresponding photonic device of the connector sleeve, coarsely aligning the optical fiber of the ferrule with the corresponding photonic device of the connector sleeve as the fiber optic ferrule is urged toward the connector sleeve, and finely aligning the optical fiber of the fiber optic ferrule with the corresponding photonic device of the connector sleeve as the ferrule is urged toward the corresponding photonic device until the optical fiber is correctly positioned with respect to the corresponding photonic device.